1. Field of the Invention
The present invention relates to a system and method for transforming tabular form data into a structured document.
2. Description of the Related Art
In a structured document, a hierarchical structure is expressed using character strings called tags. As a typical structured document, a document of an Extensible Markup Language (XML) form, namely, an XML document, is well known. XML is characterized in hierarchy of data using meaningful tags and in free extensibility of structure.
In general, to manage data used in companies so that it can be searched for, a database, such as a relational database (RDB), is utilized, and the data is treated as tabular form data obtained by mapping the data in a table. However, in accordance with advance in information technology and the increase of complexity of data to be managed, there is an increasing demand for XML documents that enable data to be freely written as mentioned above, and for XML databases used to search and analyze XML documents. In accordance with this tendency, there is a demand for a function of transforming various data items used in, for example, companies into XML documents (XML document data), and storing/managing them so as to easily process them in accordance with future business growth.
To this end, various data integration tools have recently been developed. These tools are used to collect (extract) data (tabular form data) from various data sources (e.g., RDBs) existing in companies, and transform it into a preset form (XML form). The tools are also used to store the resultant XML form data into an XML database. In the tools, a mapping form is supported, in which original data items and transformed data items are arranged as in a contrast table and corresponding data items are related to each other using lines connecting them. In a tabular form used in, for example, RDBs, each row is treated as a schema for mapping.
Jpn. Pat. Appln. KOKAI Publication No. 2005-56085 (prior art document) discloses a technique of transforming a table (tabular form data) in an RDB into a structured document, and vice versa. In this technique, one transform definition, for example, is described per one row of tabular form data in the RDB. In the process of transforming tabular form data into structured document (XML document) data, data is acquired from the RDB by issuing Structured Query Language (SQL) when each transform definition is called, whereby transformation is performed in units of rows of data in accordance with the transform definitions. In this case, the transform definitions can be described in a nesting structure.
In the data structure transform technique (prior art) described in the prior art document, the respective rows of tabular form data are made to correspond to a group of XML tags. As a result, tabular form data for each staff member of a company is transformed into XML form data (an XML document) in which data for each staff member repeatedly appears. The XML document acquired by data structure transformation is a flat-expression document in which the same structure is regularly repeated. Namely, the XML form data acquired by data structure transformation contains descriptions similar to those of the tabular form data, and these data items differ only in form. Thus, the above-mentioned prior art has failed in exploiting the advantage of XML, i.e., high flexibility in description.